The term “Tera” refers to the range in the EM spectrum from 0.3 to 10 terahertz frequencies. This terahertz radiation lies between microwave radiation and infrared radiation in the electromagnetic spectrum. It is considered an extension of microwave and mmwave frequency bands. It offers greater communication bandwidth than these frequency bands.
Terahertz frequencies share some properties of both microwave and infrared (IR) radiation. THz waves travel in LOS (Line of Sight) and they are non-ionizing like IR/magnetron waves. Moreover, like microwaves, THz frequency waves penetrate a wide variety of non-conductive materials such as clothing, wood, paper, plastic, cardboard, ceramics and so on. Terahertz radiation is strongly reflected by metals.
THz wavelengths range from 1 mm to 0.1 mm. Because THz radiation starts at a wavelength of 1 mm and gets smaller than 1 mm, it is known as submillimeter band. This frequency band is also known as T-rays, T-waves, T-lux, T-light, etc.
Terahertz frequencies find applications in spectroscopy, pulsed imaging, pulse ranging, communications, sensing, security, mine detection, detection of biochemical agents and so on. Research into the development of viable sources of THz radiation, detectors and modulators has accelerated the use of Terahertz in wireless communications.